Let-off mechanism for looms



June 9, 1925.

(J. w. BOOTH ET AL LET-OFF MECHANISM FOR LOOMS Filed Jan. 23, 1922 2 Sheets-Sheet 1 Jfine 9; 1925.

J. W. BOOTH ET AL LETOFF MECHANISM FOR LOOMS 7 2 Sheets-Sheet 2 cal Patented June 9, 1925,

JAMES WILLIAM BOOTH-AND T-HQMAS CRAVEN GOBLA$S,-01? ENGLANDw itiasze LET-DEFMECHANISJXI FQR LOOMS.

Applieationfiled .January,.23, 1922. Serial N'o. 531,()78.

aforesaid, have invented a certain new and useful Improvement in {Let-Off I Mechanisms for Looms, .of which the following description, together :withthe accompanying sheets of drawingnis as ecifioa,tion.

it relates to let1ofi' mechanism for looms.

oithe'type Oriel-ass know-n sis-friction let-0E mechanism and of the particular kind whereinrthe -cliameter o f'ithe coils of warp around the warp beam cdntrols tor regulates the friction which retards: "the wrotary .mo-

tions "of saidiwarpbeannoand Lour said in- VQDt- IQIIHCQIJSlStvS in a novel; formation and constructionof clever. devicesand Inechanism tor altering; ceiztainoof the iiulc-rums of same 1 so i as totvarywtheqpower :or force exercised by; said ilegvers (and therefore the, friction which acts) I (upon the [warp l abeam to retard its -motions.; i r

In the accompanying sheets of: drawings which are illustrative oifiour invention- Fig. 1 isaa isectionaleend elevation of a portion of theirameworkaof. a loom :and

the warp beam mounted thereon Wlth-r0ll1.

improved mechanism applied thereto.

Fig. 2 is a rearuelearationoithewapparatus S110V'111b1V Fig. 1 .asuseenoin the direction looking from right'irto left of saidfigure.

Fig.3 isa plan iof partsrshownbyl ig. .1;

Fig. 4 is .a 'sectional 'eleyation 0f certain oifaourciinprowedpazrts. p

Fig. 5 is 3"5Plflifl Of1bi1lQiITbS shown-by Fig. 4:. y T Fig. 6 isa sectional end elevationishowing. the formation of a bracket {for supporting the :fulcrum .o'tftheuweisglrted.lever which acts, LhPOld the brake ioiththebwarpg-bcam;p. The drawings .shoiw .0mm apparatus upon one end of. a 1wanp-beam, however wo may use same at both- :endsithereozf when desired; Our; invention is shownwas applied ;to an m'din'any loom wherein theiwarp' beam 3 is mounted- :in' the usual manner upon abear ings fixed to the lendiirame 7 oil. the loom so. th atthe w arp maybe Withdrawn there from under suchiconditions thattasisame is being carried out :the :well: known detector leven 8 '(whichxrests against the zGOhlS of warp- .3%?) iiS madeitoscontnol the. novel devices hereinafter described, as it moves from the position shown in full lines Fig. lto the position shown in broken lines of the same li-gure, by which the object of our inventionis attalned.

Inconnection with thesaid warpbeam and other parts ave make use of a chain, rope or other friction imparting device 2 which according to the drawing encircles the end of the warp beam 3 or which may encircle pulleys or drums mounted-thereon as is well understood. This friction device. in/ thei'orm of the chain 2, is coupledoby a hook 18 to the end of a weighted lever 4;, the weight 4* "of which acts thereon so that. the; power 01"? said Weight i over the hook 18'" and consequently overthe gripping chain 2, is exerted through said lever- 4;,"

which rostswwith its fulcrum n-pon the bowl orru-nner 5 at the point et show-n by Fig. 4:. The runner or bowl "5 is supported by the bracket 6 which is fixed to the end frame Tofthe loom so that as said bowl 5 isipere mittedto move over the bracket 6 [trom the position shown in full lines- Fig. 2 tothje position shown in brokenlines iofithezsame figure, the relativellengths oi the arms otf the lever 4: are altered so that the power of the weight overthe brake chain 2 is gradualily diminished. 1 I This, diminishing of thepower oi the weight 4? over the-brake 2 isigrachiallyv brought into eiiect "as! the diminished :d-i ameter ofvthecoils of warp Li -upon the beam 3 decrease in number and therefore in diameter and this is-ieffected by coupling the. detector lever 8 to the bowl- 5 under such conditions as @to enable the weight 1 F to carry "said {bowl 5. over the supporting. bracket 64in the mannerabove-stated.

r The detector lerer 8: is pivotedv upon-a shaft 9 which is supported in :suitable ibearings by the glira-niework .ot-the :loom so that at the otheiiiend of the shaft 9 another level. 1Oinay1be fined." This lever =10 isconnected by afiexihleconnection 11 00%2'021 111 piece 12 (the functions of which are hereinafter de soribec-Ui which is ']Z):iVOtB-Cl- UPOI1 rbearings fixed upon "the end ZfTfl'illQ Qifl1116 100111 as shown by Figs. .1 and 2, and the said flexible connection e-iztends over this cam piece so that thy a cross piece 13, twootherwflexe ble connections 14: and 1 B glnay 'be'qo ned'to it and be made to extend over guiding ;pu]1- leys 15, 15 so thatithese latter may beec nected to links 16, 16 which;takejloosely 'parts being arranged as described, as the over th 3111 5 u on which thebowl 5 is pivoted.

The links 16, '16" are further connected to a cross piece 0 by appropriate connections so that the extension 14 of the flexible connections may pass over the guide pulley 15 to support the weight 14. By these several coils of warp 3 upon the beam 3 diminish in number to permit the lever 8 to follow said diminishing diameter said movements of the lever 8 are carried out by the weight 14 dragging the bowl 5 along the bracket 6.

To enable the bowl 5 tomove freely under the actions of the weight 14 as above described, wemount upon the pin 5 (which has the bowl 5 mounted upon it) two bowls 17 and l't' 'one at one side and the other on the other side thereof, and these bowls 17, 17 are of less diameter than the bowl 5 (the slot- (5 in the bracket 6 being arranged to receive the larger diameter bowl 5) so that they alone are in contact with the upper surface of the bracket 6 while the upper surface of the periphery of the bowl 5 supports the lever 4 by the lower edge of said lever 4 resting thereon, thus as the weight 14 drags the pin 5 along its horizontal path, the bowls 17, 17 roll over the upper surface I) of the bracket 6; while the bowl 5 rolls beneath (and in an opposite direction) the lower edge of the lever 4 by whicharrangement the greatest freedom for the actions of the parts described is secured. To secure further freedom for the actions of the bowls 5 and 17, 17* the upper surface 7) of the bracket 6 is slightly inclined to the horizontal plane the inclination being shown by the difference between the path indicated in broken lines A B and the path over the upper surface I) of the bracket 6. Further than this the inclination of the lower edge of the lever 4 is in the opposite directionto that of the upper surface of the bracket 6 somewhat as is shown by the broken lines C "D as compared with said under surface of the lever 4 thus the moving of the bowls described is greatly facilitated;

To further facilitate the rotations of the bowls 17, 17 and 5, antifriction bearings may be used in conjunction with these said bowls or runners so that they may more freely revolve about the pin 5.

The lever 4 has its extremity of a bifur cated form so that the extension of the hook 18* may take through same and through a pivotal part 18 to have the adjusting nut mounted upon it at its upper end, thus the position of the lever 4 may be adjusted relatively to the parts in connection with which it has to operate. The end of the bracket 6 is bifurcated to receive the T- shaped extension 41 ofthe lever 4 as shown by Figs. 2 and 3, by which meanssaid lever is retained in posit on, 1

In order to keep the proper ration of variation between the diameter of the coils 'of warp 8 upon the beam 3 and the leverage of the arms of the lever 4 (as brought about by the moving of the fulcrum bowl 5 beneath the lever 4)rwe mount the intervening cam piece 12 in the position shown, and we form it of such a character as to enable it to keep the desired ratio intact throughout. It has been found in practice that unless the cam 12 is provided the diminishing,diameter of the coils ofthe warp on the beam will not permit the movement of the weight over the weighing lever "in the exact. proportion desired, because the decreasing diameter cannot be apportioned to thedecreasing leverage in any exact ratio. Therefore, the cam 12 is provided, and this also serves to keep taut the flexible connection between the lever 10 and the cross piece 13.

In order to enable the-weaver to readily release the: beam 3 from thegrip of the brake devices, we mounta cam like hand lever l9 upon the bracket 6 in order that by the actuation of this lever 19 the weaver may cause the cam part 19 to pass beneath the bowl or runner 20 mounted upon the,

lever 4 so as to raise said lever and relieve the chain 2 of the force exerted thereby.

In the accompanying description and as shown by the sheets of drawings we have illustrated the brake or'friction device as consisting of a chain which encircles the hub on the end of the warpbeam 8, but it-is ob vious thatwe make useof rods or shoe-or clamping devices of'any of the varied well known forms instead of using-said chain in which case the 'connectingdevice will be made to suit the altered-form of friction device. 7

Such being the nature and object of our said invention, what we claim is:

1. In let-off mechanism for looms, a warp beam, a brake device engaging with said warp beam, a weightedlever acting upon said brake device, a movable fulcrum for said weighted leverymeans for connecting said'movable fulcrum to a detector contacting with the coils of warp on the warp beam, and means for keeping said detector against said warp beam.

2. In let-off mechanism for looms, a warp beam, brake mechanism engaging with said warp beam, aweighted lever for operating said brake mechanism, connections between said lever and said brake mechanism, a; bowl or runner forming the fulcrum fol said brake lever, a bracket for supporting said bowl or runner,-" connections'between said bowl. or runner and a detector which contacts with the coils of warp on the warp beam, whereby the fulcrum of the brake lever is positively moved along the supporting bracket as the diameter of the warp coil is reduced, and a weight for operating said runner to k p the detector in contact with the coils of warp on the warp beam.

In let-oft mechanism for looms, a warp beam, a flexible brake device encircling said warp beam, connections from said flexible brake device'to a weighted lever, a movable support upon which the brake lever ispivob ed, means for moving said support in accordance with the diminishing diameter of the coils of warp on the warp beam, and a detector device in conjunction with said means for operating the movable support.

4. In let-oil" mechanism for looms, a warp beam, a brake device engaging with said warp beam, a weighted lever for operating said brake device, a movable fulcrum for said weighted lever, means. for efl'ecting movement of said movable fulcrum in accordance with the diminishing of the diameter of the coils of warp upon the warp beam, and a cam piece cooperating with said fulcrum moving means to retain the ratios of the leverage and the diameter of the warp beam constant.

5. In let-oft mechanism: for looms, a warp beam, a brake device in connection with said warp beam, a we'ighted'lever operating said brake device, a movable fulcrum for supportingsaid weighted lever, bearings for supporting said movable 'fulcrum, sets of bowls or runners for intervening between the bearings of the'lever so as to act as said movable fulcrum, and means for operating said bowls.

6. In let-oft mechanism for looms, a warp beam, brake mechanism for engaging with said warp beam, a weighted lever for operating in connection with said brakev mechanism a movable support upon which the weighted levervis pivoted, said support being arranged so that it maybe adjusted to decrease the force of the weighted. brake mechanism as the diameter of the coils of warp upon said warp beam diminish, and means whereby said diminishing diameter of warp threads is detected and used for con rolling the position ofthe support for the lever, in combination with hand actuated devices whereby the weaver may relieve the brake from the actions of the weight.

JAMES WILLIAM BOOTH. THOMAS CRAVEN CORLASS. 

